Improvement in process and apparatus for the manufacture of paper



2 Sheets-Sheet 1. G; E. MARSHALL; PROGESSDP AND APPARATUS FOR THBMANUFAG'IURB OF PAPER. No. 105,585. Patent-ed'July 19, 1870.

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. 2 Sheets-Sheet 2. A A G. E. MARSHALL. v PROCESS OF AND APPARATUS FOR THE'MANUPAGTURE OF PAPER.

No, 105,585. Patented July 19,1870.

diluted; swat patent (dilute.

GEORGE E. MARSHALL,

o r L A on E L, INDIAN A.

Letters Patent No. 105,585, dated July) 19, 1870.

I My

The Schedule referred to in these Letters Patent and making part of the same To all whom it may concern:

Be'it known that. I, GEORGE E.M:ARSHALL, of Laurel, inJshe county of Franklin and. State of Indiana, have inventedcertain new and useful Improvements in the Manufacture of Paper and'Machines for the same; and I do hereby declare that the following in a full, clear, and exact description thereof, reference being had ,to the accompanying drawing making part of this specification, and .to' the lettrs of reiercnce marked thereon, like letters indicating like'parts whereever they occur.

To enable others skilled in the art to construct and use ;my invention, I will proceed to describe it.

My invention relates to the manufacture of paper;

It consists in an improved method of washing, bleaching, and cleansing paper-stock or pulp made from straw, woodymanilla rope, e'sparto grass, and -old printers paper, and also in a novel, arrangement of mechanical devices forcarryiug out the said process.

In the manufacture of white paper from wood, straw, 860., his or great importance, after such stock has been boiled in analkaliue solution, that the pulp thus produced should be thoroughly cleansed from the alkali and saccharine or glutinous matters remainingin it before the said pulp is subjected to the action of chlorine for bleaching it for white paper. And, after the'stock -.has been bleached with chlorine, it is equally impor-- tant that all traces of the chlorine be removed from the pulpbefore it is run out,on the paper-machine into anywhite paper. 1

It is afact well known to the best paper-makers that the more-thoroughly thepnlp'is cleansed from alkali, and glutinous matter remaining in it, after it hasbeen boiled, the less chlorine it takes to produce 7 a given shade of white, and it is equallywell known that the action of the chloriueptends to weaken and destroy the fiber, and that the less chlorine used,1t-he strongerand more pliable is the paper produced from straw and like fibrous material. Hence the necessity of a thorough washing or cleansing of the pulp before it isblcached, as well as afterward.

, Another fact is,t-hat the longer the stock is allowed to remain in the-pulpy state, after being bleached, be-

fore the chlorine is washed out, the more hard, crisp,

and brittle is the paper produced; hence it is of importance that such fibrous material he bleached quickly, and the chlorine immediately washed out.

Still another fact, but one not generally known, is that, it'a certain amount of chlorine is to be used for bleaching a certain amount of stock, if, instead of using the whole quantity of chlorine atone time, a portion only is used to bleach the stock, and the stock. then dried sufficiently to be handled, and the chlorine washed out, and then the remaining chlorine used to rebleach the stock, a much whiter and cleaner paper is produced.

For example, if twenty pounds of chlorine are to be used to bleach a hundred pounds of pulp,'instead of using all the chlorine inone operation, first use,

say, fifteen pounds to bleach the one hundred pounds of pulp, and then, after thoroughly washing the puip, use, the remaining five pounds of chlorine to rebleach the whole quantity of pulp. But, to perform these operations in mills as now constructed, would require a great amount of extra. time .and labor.

, As nowpracticed in the. best paper-millsin the country, the pulp, as it comes from the hoilers, is placed in an ordinary rag-engine, and partially washed. It is then emptied into a taukor stufi'c est, and drawn oh, by means of a pump, to the mixing-box of an ordinary nit-paper machine, where it is mixed with thewater extracted from pulp previously passed through the machine.

The ulp thus mixed is then passed through the screen% pulp-dresser and onward to the wire-ganze cylinder, if a'cylinder machine is used, where the water is partially extracted and carried ofi' through the cylinder, and the pulp thereby formed into wet paper on the surface of the cylinder, and from whence it is -taken off bythe wet felt.

The ,wet machine has, I am aware, been in use for the purpose of running out straw and wood-pulp, and removing uncooked portions of the same as it passes through the screen or pulp-dresser, a small portion of the alkali and saccharine matter being also incidentally removed as the wet paper passes through between the press-rolls.

In carrying out my process, I also make use of, among other devices, the ordinary wetmachine, with certain improvements.

These improvements consist, first, in allowiugthe water which-passes through into the perforated cylinder to run ofi to waste, carrying with it, of course, the

alkali and saccharine matter held in solution, and, I

to work the pulp through the screen or dresser, and

to form the paper on the cylinder, by discharging fresh, clean water into the receiving-vat or mixing-trongh, and an additional supply of clean water into the pulp after it has passed the screen, but before reaching the cylinder, as-hereinafter more fully described.

As a much larger'amount of water can be passed through the cylinder than through the screen, the amount of water added to the pulp'aiter passing the screen may be very considerable, so that, by these improvements, a much great-cr quantityof water can be washed through the pulpthan by the old method, and consequently the pulp more thoroughly cleansed.

In the drawing Figure 1 is a top plan view of a common cylinder wet-paper machine having my improvements applied;

Figure 2, aside view of the same, with portions broken away to show the interior; and

Figure 3, aside elevation of a train of three wet machines, with the accompanying bleaching-tanks, stuff-chests, 8m, as arranged for carrying out my process.

A, figs. l and2, represents a wet machine of the ordinaryconstruction, so far as regards the general features, of screens, vats; perforated cylinder, endless feltprcss-rolls, &c., and in whiehit represents the receiving-vat for the pulp;

b, the screen or pulp-dresser;

c, the vat which receives the pulp passing through the screen; s i

d, the trough in which the wire-gauze cylinder is mounted, and which is kept filled with pulp and water;

0, the gauze cylinder; and

j, a pipe communicating with the interior of the cylinder, and with an exhaust-pump for causing a suction inward through the cylinder.

f discharge the water exhausted through it back into the receivingrvat a, where it became mixed with new pulp, and in this manner the same water was used over and over again.

In my machine I allow this water to run off to waste,

as shown, and provide a pipe, 12-, which discharges fresh, clean water into the receiving-vat a, to reduce the pulp to the required thinness.

To one side of the machine I attach a box, J, divided into two compartments by means of a vertically adjustable gate, g, having an opening, k, through it,

as shown in fig. 2.- I

One compartment of the box J, I provide with a hole, 2', communicating with the vat c, and the other compartment I provide, at its bottom, with a wastepipe, j, and also arrange a water-supply pipe, It, so as to discharge into the compartment which is connected with the vat, as shown in figs. 1 and 2.

Water being discharged through the pipe 7: into box J, a portion flows through the hole i into vat c, and the remainder through gate g and oil through waste-pipe j.

Byadjusting the gate g, the water may be maintained at any desired height in the box, and as the box has free communication with the rat, the level of the pulp in the latter is always the same as that of the water in the former, so that, by adjusting the gate g, the level of the pulp may be varied as desired.

As the gate is raised and lowered, the quantity of water which flows into the rat is also varied.

By this arrangement of parts I am enabled to work a. very large quantity of water through the machine with the pulp, so'as to thoroughly dissolve and wash out all alkali and saccharine matters, ink, chlorine, and other foreign matters, which are carried oil with the water through the cylinder 0..

In the old styles of machine, where less water could *beworked through, the alkali and saccharine matter were only partially dissolved, and the only portions that were removed were those that were squeezed out from the wet paper in passing through the press-rolls, as all that .was held in solution by the water passing through all?! gauze cylinder was returned with the water to the receiving-vat, and remixed with fresh pulp or stock.

In carrying out my process, I provide two or more of the wet machines A, and double the number of bleaching-tanks B,'and arrange them as shown in fig. 3, placing first a machine and then two tanks, side by side, and so on.

Near the first machine I locate a tank or stuff-chest, G, and connect it, by a pump, D, with the receivingvat a of said machine,

At the back end of the machine I arrange an elevator, I), which may be shifted so as to communicate with either one of the two tanks 15 there 1ocated.

Each of the tanks B,I provide with a dischargepipe, emptying into the receiving-vat of the second machine A,'and at the back end of this second machine arrange an elevator discharging into the second .pair of tanks, and so on continuously, each machine connecting with a pair of tanks, and these tanks with the next machine. The last tank I connect pith either a rag-engine, as shown, or with a tank or stutfchest, according to circumstances. a

In operating the train of machines, as shown in fig.

- 3, the pulp, after being boiled and then washed in an ordinary rag-engine for about an hour, is discharged into the tank 0 as unwashed pulp; or, if properly boiled, the pulp may be taken directly from the boiler to the tank 0 without being passed through the rag engine. 7

From the tank 0 the pulp is carried, by the pump D, to the first wet machine A, where the pulp is thoroughly washed and cleansed, and freed fi-om'alkali, Heretofore it has been customary to have the pipe saccharine matter, ink, chlorine, and other impurities contained in it.

The pulp, in passing through the machine, is converted into wet paper, and in this form it is delivered to the elevator E, which carries the wet paper over 'into the first bleaching-tank B, which is charged with a solution of chlorine, and provided with stirrers or agitators for breaking up the paper and reducing it to the'form of pulp again.

When the first ot' the tanks B is suflicientl y charged with the wet paper, the elevator E is shifted so as to discharge into the adjoining tank, which is, like the first one, charged with chlorine, and provided with agitators.

While the second'of the tanks bl is being filled, steam is admitted into the one which is full, and the contents heated to about 100 above the temperature of the surrounding air, which causes the chlorine to act with great rapidity.

This is continued for about two hours, the agitators being kept in motion the while, when the pulp is dis charged in the receiving-vat of the second wet machine A, through which it is passed to wash out the chlorine and coloring matter dissolved by it while in the tank B.

This second machine again forms the pulp into wet paper, and then discharges-it onto the second elevator E, which delivers it into one of second pair'oi' bleaching-'tanks B, where it undergoes the same treatment as in the first, except thatthe chlorine only about one-third the strength of tlie'first.

The pulp is then discharged fromthis tank B to the third machine A, where it is washed from the chlorine, formed into wet paper, and then, by the elevator delivered into the third tank B, where it is again broken up and reduced to'pnlp.

From this third tank the pulp is'dischargcd into an ordinary rag-enginc and the coloring ,and sizing matter added to it, and then discharged into a tank or stud-chest, from whence it is delivered onto the usual paper-machine, and by it formed into finished paper. p

It is obvious that the bleaching-tanks may belocated in the basement of the building, immediately under the machines; and pumps used to draw the pulp up from each tank to the next machine, and also that. the last tank could be dispensed with, and the wet paper putinto the rag-engine by hand, but I prefer to locate them as shown, for the reason that I thereby -save hand-labor entirely, and also the cost of extra pumps.

The advantages of my process are- First, a much more rapid and perfect cleansing of the pulp t'pom the alkali and saccharine matter, as in solution is of the same length of time I wash about ten times the m quantity of water through it that eouldbe done by the old method. r

.Seeond, it requires no drainers, and therefore the Jabor required under the old method, to remove the stock from the drainers to the rag-engine, is dispensed with, and, besides, in the old method, more or less of the stock was lost in the many bandlings from drainers to cars, cars to rag-engines, 850., and still more of it injured by dirt of various kinds getting into it while being thus handled.

By my arrangement it will be seen that the only handling required is in passing the stock, in the first instance, from the boiler to the washing-engine.

and hence will conduce to the use of straw, wood, 8m,

for the finest paper, instead of the far more expensive stock now used.

Having thus described my invention, What I claim is-- 1, The herein-deseriibed process of preparing paperpulp by subjecting the same to alternate bleachings v and washings, substantially as described.

2. The process 0f washing or cleansing paper-pulp by the addition of a supply of fresh water to the vat, and the earrying away of the water drawn off through the gauze cylinder, substantially as described;

'3. The. cnmbination of the fi'esh-wa-ter-supply box J with the wet-paper machine, when constructed and arranged to operate substantially as set forth.

, 4. The fresh-water box J, having an inletspipe k, a division with a regulating-gate g and waste-pipe j, all arranged substantially as set forth.

5. The combination of a series of wet-paper machines, provided with the bleaching-tanks, arranged to operate substantially as described. I GEO. E. MARSHALL.

Witnesses:

R. J. DAY, PETER O. AKERS. 

